content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  
  package io.reactivex.observable;
  
  import io.reactivex.common.Disposable;
  import io.reactivex.common.annotations.NonNull;
  
  /**
   * Represents the subscription API callbacks when subscribing to a Completable instance.
   */
  public interface CompletableObserver {
      /**
       * Called once by the Completable to set a Disposable on this instance which
       * then can be used to cancel the subscription at any time.
       * @param d the Disposable instance to call dispose on for cancellation, not null
       */
      void onSubscribe(@NonNull Disposable d);
  
      /**
       * Called once the deferred computation completes normally.
       */
      void onComplete();
  
      /**
       * Called once if the deferred computation 'throws' an exception.
       * @param e the exception, not null.
       */
      void onError(@NonNull Throwable e);
  }
  